Diindolylmethane
OTHER NAME(S): diindolylmethane, DIM
Overview
Diindolylmethane is a type of chemical called an indole that is available over the counter as a supplement. Although it is not naturally found in foods, your body makes diindolylmethane out of another chemical in certain vegetables. Diindolylmethane supplements are used for many reasons, but their benefits are not well defined. Common side effects include darkened pee, headache, and upset stomach. Before taking diindolylmethane, make sure to tell your health care provider about any health conditions you have or medicines you are taking.
Uses
What is diindolylmethane used for?
Diindolylmethane is used for many reasons, but its benefits are not well defined. Some common reasons for using diindolylmethane include the following.
- Menopausal symptoms
- Premenstrual syndrome (PMS)
- To reduce inflammation
- To reduce the risk of certain forms of cancer
Note: The FDA has not reviewed diindolylmethane for safety and effectiveness. Learn more about dietary supplements here.
Diindolylmethane is available as a dietary supplement in various strengths and dosage forms. It is often added to products that contain other ingredients such as sulforaphane, minerals, and herbs.
How does diindolylmethane work (mechanism of action)?
Diindolylmethane is a type of chemical called an indole. It comes from another chemical, indole-3-carbinol (I3C), that is naturally found in cruciferous vegetables such as broccoli, Brussels sprouts, cauliflower, and cabbage. When you eat these vegetables, the acid in your stomach changes I3C into diindolylmethane.
Diindolylmethane is an antioxidant that has gained popularity for reducing the risk of certain forms of cancer. But this popularity is not supported by evidence. Although animal studies show that diindolylmethane may be able to help reduce the risk of prostate cancer, breast cancer, cervical cancer, or liver cancer, these findings have not been confirmed in humans. In fact, some studies show that it may not have any benefit. If you have been diagnosed with a precancerous condition, such as cervical dysplasia or prostatic intraepithelial neoplasia (PIN), speak with your health care provider about the best options for reducing your risk of cancer.
There is also interest in using diindolylmethane to balance estrogen levels and manage conditions such as premenstrual syndrome (PMS) and menopause. But the effects of diindolylmethane on estrogen are not well defined. It is not clear if diindolylmethane increases, decreases, or has no effect on estrogen levels.
How should I store diindolylmethane?
You should store diindolylmethane according to the product label. Most dietary supplements should be kept in a cool, dry location that is out of the reach of children and pets and not in direct sunlight.
Side Effects
What are the most common side effects of diindolylmethane?
The most common side effects of diindolylmethane are listed below. These side effects may vary depending on the dose you are taking or the specific product you are using. Tell your health care provider if you have any of these side effects that bother you.
- Darker pee (urine)
- Headache
- Upset stomach
There may be other side effects of diindolylmethane that are not listed here. Contact your health care provider if you think you are having a side effect of a supplement. In the U.S., you can report side effects to the FDA at www.safetyreporting.hhs.gov or by calling 888-SAFEFOOD (888-723-3366). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.
What are the serious side effects of diindolylmethane?
While less common, the most serious side effects of diindolylmethane are described below, along with what to do if they happen.
Severe Allergic Reactions. Diindolylmethane may cause allergic reactions, which can be serious. Stop taking diindolylmethane and get help right away if you have any of the following symptoms of a serious allergic reaction.
- Breathing problems or wheezing
- Racing heart
- Fever or general ill feeling
- Swollen lymph nodes
- Swelling of the face, lips, mouth, tongue, or throat
- Trouble swallowing or throat tightness
- Itching or skin rash
- Bumps on the skin called hives that can be red, pink, white, or brown depending on your skin tone
- Nausea or vomiting
- Dizziness, feeling lightheaded, or fainting
- Stomach cramps
- Joint pain
Precautions
Who should not use diindolylmethane?
Allergies to Ingredients. People who are allergic to any of the following should not take diindolylmethane.
- Diindolylmethane (DIM)
- Any of the ingredients in the specific product
Your pharmacist can tell you all of the ingredients in the specific diindolylmethane products they stock.
What should I know about diindolylmethane before using it?
Diindolylmethane is a dietary supplement. It cannot be marketed to treat or cure a disease.
Read and follow the directions on the specific product you are taking, or take it as recommended by your health care provider.
Keep diindolylmethane out of the reach of children.
Diindolylmethane is not found in any plants. But your body makes diindolylmethane out of a chemical naturally found in cruciferous vegetables, called indole-3-carbinole (I3C). Some dietary supplements contain I3C. Taking these supplements can increase the levels of diindolylmethane in your body.
The FDA has not tested diindolylmethane products to confirm that they contain the ingredients stated on their labels. Some dietary supplements have been tested by third-party organizations to confirm that they contain the ingredients listed on their labels and do not contain any harmful chemicals. Learn more about how to choose a safe dietary supplement product here.
What should I tell my health care provider before using diindolylmethane?
Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them know if diindolylmethane is right for you.
In particular, make sure that you discuss any of the following.
Current and Past Health Conditions.Tell your health care provider if you have any of the following.
- History of cancer
- Precancerous conditions, such as cervical dysplasia or prostatic intraepithelial neoplasia (PIN)
- Receiving treatment for cancer, including radiation or chemotherapy
Other Medicines and Supplements.Diindolylmethane may interact with other medicines and supplements. Before taking diindolylmethane, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.
Pregnancy. It is not known if or how diindolylmethane could affect pregnancy or harm a fetus. Tell your health care provider if you are pregnant or plan to become pregnant.
Breastfeeding. It is not known if diindolylmethane passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed.
Interactions
Does diindolylmethane interact with foods or drinks?
Diindolylmethane may reduce the levels and effects of caffeine in your body.
It is unknown if drinking alcohol will affect diindolylmethane.
Does diindolylmethane interact with medicines (drug interactions)?
Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.
In particular, make sure that you discuss if you are using any of the following before taking diindolylmethane.
- Chemotherapy, which is a type of medicine used to treat cancer
- Hormone replacement therapy or any medicines that contain hormones, including certain types of birth control
- Tamoxifen, which is a medicine used to treat breast cancer
Diindolylmethane may alter the blood levels of some medicines. Tell your health care provider about all medicines that you take or have recently taken.
The interactions between diindolylmethane and medicines are not fully understood. As with most dietary supplements, the research on drug interactions with diindolylmethane is incomplete. Always check with your health care provider before taking diindolylmethane with any medicines.
Dosing
What should I do if I accidentally use too much diindolylmethane?
If you or someone else has used too much diindolylmethane, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.
Diindolylmethane comes in many doses and may be combined with other ingredients. Read the product label closely, and speak with a health care provider about how to take diindolylmethane safely. Do not take double or extra doses, even if you miss a dose.
References
- American Cancer Society: “Study finds antioxidants risky during breast cancer chemotherapy.”
- British Journal of Cancer: “Effect of diindolylmethane supplementation on low-grade cervical cytological abnormalities: double-blind, randomised, controlled trial.”
- Cancer Epidemiology, Biomarkers & Prevention: “A phase I study of indole-3-carbinol in women: tolerability and effects,” “Single-dose and multiple-dose administration of indole-3-carbinol to women: pharmacokinetics based on 3,3′-diindolylmethane.”
- Carcinogenesis: “3,3-Diindolylmethane (DIM): a nutritional intervention and its impact on breast density in healthy BRCA carriers: A prospective clinical trial.”
- European Journal of Cancer Prevention: “Phase Ib placebo-controlled, tissue biomarker trial of diindolylmethane (BR-DIMNG) in patients with prostate cancer who are undergoing prostatectomy.”
- Memorial Sloan Kettering Cancer Center: “Diindolylmethane.”
- National Cancer Institute: “Diindolylmethane.”